Dry powder fire extinguishers smother fires by forming a barrier between the fuel and the source of oxygen.
As they do not cool the fire, there is a small risk of re-ignition.
Pros: work on most types of fire; they suppress fires very quickly; specialist dry powder extinguishers are the only extinguishers that work on flammable metals.
Cons: slight danger of the fire re-igniting; when discharged, the powder can spread over a large area leaving a residue; can obscure vision when discharged and can be inhaled if used in enclosed areas.
Dry powder fire extinguishers are ideal for open or outdoor environments with the risk of several different types of fire, especially those involving chemicals, fuel, or vehicles. Examples include:
• Garage forecourts
• Large, commercial boiler rooms
• Flammable liquid storage facilities
• Large workshops
• Fuel tankers and other vehicles
Whilst powder fire extinguishers do extinguisher electrical fires involving equipment under 1000v, we recommend also having CO2 extinguishers on hand where there is this kind of fire risk, such as in a team kitchen, or where electric heaters are used.